Adaptive weight update method for a discrete multitone spread spectrum communications system

1. A highly bandwidth-efficient time division duplex communications method, comprising the steps of: receiving at a base station a first spread signal comprising an incoming data signal spread over a plurality of discrete frequencies; adaptively despreading the signal received at the base station by using first despreading weights; computing an error value for said first spread signal; comparing the error value with a threshold error value; maintaining first spreading weights as a current spreading weights at the base station to apply to an outgoing data signal in response to said error value being less than said threshold error value; adaptively calculating second despreading weights at the base station from said first spread signal and calculating second spreading weights as the current spreading weights from said second despreading weights to apply to the outgoing data signal in response to said error value being greater than said threshold error value; spreading said outgoing data signal at the base station with said current spreading weights, to distribute the outgoing data signal over a plurality of discrete tones, forming a second spread signal; and transmitting said second spread signal as a time division duplex signal.

2. The highly bandwidth-efficient time division duplex communications method of claim 1, wherein said error value for said first spread signal is a bit error rate.

3. The highly bandwidth-efficient time division duplex communications method of claim 1, wherein said error value for said first spread signal is a Reed-Solomon error value.

4. The highly bandwidth-efficient time division duplex communications method of claim 1, wherein said error value for said first spread signal is a difference value between said first spread signal and a reference signal at the base station.

5. The highly bandwidth-efficient time division duplex communications method of claim 1, wherein said error value for said first spread signal is a mean square error value.

6. The highly bandwidth-efficient time division duplex communications method of claim 1, wherein said threshold error value is a limit error value less a margin error value.